1. Field of the Invention
The present invention relates to a liquid crystal spatial light modulator for electrically modulating a laser beam.
2. Description of the Prior Art
As a liquid crystal device capable of electrically modulating a laser beam, liquid crystal displays used for liquid crystal televisions have heretofore been employed experimentally very often.
However, the resolution offered by any one of the conventional liquid crystal devices, which have been employed mainly for liquid crystal televisions, remains as low as 2-2.5 l p/mm. Consequently, those conventional liquid crystal devices have failed to answer the requirements including 10-100 l p/mm in resolution necessary for optical data processing. Moreover, the contrast ratio is as low as 1/5-1/20, so that it can not meet those requirements including 1/100-1/1000 in contrast necessary for optical data processing. In the case of the conventional liquid crystal device, when analog optical data processing is performed, the wavefront distortion after laser beam modulation becomes greater because of the inferior flatness of the substrate. As a result, the wavefront needs correcting, using matching oil, a phase conjugation wave or the like.